在R中设置数字格式

format(x, digits = NULL, nsmall = 0, scientific = FALSE, big.mark = "", decimal.mark = ".", ...)

# 设置小数点后两位
formatted_number <- format(1234.5678, nsmall = 2)
print(formatted_number) # 输出: "1234.57"

# 使用科学记数法
formatted_scientific <- format(123456789, scientific = TRUE)
print(formatted_scientific) # 输出: "1.234568e+08"

# 添加千位分隔符
formatted_with_separator <- format(123456789, big.mark = ",")
print(formatted_with_separator) # 输出: "123,456,789"

# 确保数据是数值类型
if (!is.numeric(input_number)) {
  stop("输入的数据不是数值类型")
}

# 正确设置参数
formatted_correctly <- format(input_number, nsmall = 2, big.mark = ",")